Search

A novel sulfur-modulated metal–organic framework photocatalyst, MIL-101(Fe), with CQDs anchored on its surface has been successfully synthesized to efficiently separate photo-induced carriers for the degradation of Rhodamine B and Cr6+ removal.

A g-C3N4/NH2-MIL-88B(Fe)/CD@GO membrane (M2) was prepared by a simple vacuum filtration method.

ABSTRACT: This paper presents a new fully coupled Hydro-mechanical-Chemical (HMC) model also accounts for the ultrafiltration effect resulting from pressure gradient in the expression of the solute mass flux. Based on this new HMC model, one derives a set of analytical solutions considering the fully coupled porochemoelastic responses for drilling an inclined borehole. Using the new solutions conducts several studies of the ultrafiltration effect on pore pressure, stress, and the time-dependent shear failure behaviors including intact rock matrix and weak plane around a horizontal borehole drilling through the shale formation. The results show that the ultrafiltration effect increaces the mud weight required to avoid borehole collapse when the solute mass fraction ( or solute concentration) of drilling mud is larger than that of the formation fluid. The location of borehole breakout does not always occur at the borehole wall. It initiates inside the formation at an earlier time whereas returns to the borehole wall with increasing time. This regularity is exactly in response to the corresponding variations of pore pressure and effective stresses. 1. INTRODUCTION Borehole stability is in principle controlled by the field variables around a borehole drilling through a porous rock (Gao et al. 2021). In the case of drilling chemically active porous shale formation, the main field variables associated with the pore pressure and stresses are disturbed and reestablished due to differences including pressure, solute/solvent mass-fraction (concentration or activity), and stresses at the borehole wall between pre-drilling and post-drilling. The solute mass-fraction (concentration or activity) difference is compared between the pore fluid of shale formation and drilling mud. Studies for the variations of field variables have been made with respect to the poroelastic effect (Detournay and Cheng, 1988), chemical osmosis effect resulting from solute mass-fraction(concentration) difference (Heidug and Wong, 1996; Ghassemi and Diek, 2003; Yu et al., 2003; Ekbote and Abousleiman, 2006; Roshan and Rahman, 2011; Kanfar et al., 2016), and water activity difference (Mody and Hale, 1993; Nguyen et al.2009).

The CO molecular ionization and Coulomb explosion are systematically investigated utilizing a high-resolution time-of-flight mass spectrometer. It is found that the main dissociation channels of hi...

With the development of science and technology, the application of the Internet of Things (IOT) is becoming more and more widespread. Applying BP neural network algorithms (NNA) to the IOT system will help improve the performance of the IOT system. The research purpose of this paper is to solve the problems of long-parameter measurement cycle and untimely feedback of the existing IOT online measurement system. In this paper, a multi-parameter (MP) IOT online measurement system based on BP NNA is designed, and a simulation test experiment is performed. The MP online measurement IOT system based on the BP NNA completes the parameter collection, analysis, and display through the perception layer, network transmission layer, and application layer. The core is that the system application layer adds the BP NNA to optimize real-time acquisition parameters, processing to reduce parameter measurement time. It can be known from algorithm simulation experiments that the online measurement system based on the BP NNA proposed in this paper uses the BP NNA to predict the absolute error value of the final moisture content and the measured moisture content within 0.3, and the absolute error of the moisture content value in actual production. It is acceptable in the range of 0.5, which speeds up data collection time. This system has a very good effect on improving the feedback adjustment speed of the manufacturing process system.

Improvements to the degradation of NO by photocatalysts requires enhanced oxidation activity. In this work, the heterostructural photocatalyst BiOBr0.5I0.5/BiOBr/BiOI was prepared and showed enhanced photocatalytic efficiency for the removal of NO. We examined the photocatalytic removal of NO and confirmed that the improved efficiency of NO removal in our systems was due to the synergic effect of enhanced carrier and exciton photocatalysis. The superoxide and singlet oxygen generated from these two processes lead to the highly efficient removal of NO. Meanwhile, the photocatalytic NO removal mechanism of BiOBr0.5I0.5/BiOBr/BiOI was explored by in-situ FT-IR. This investigation provides a new approach to the design of efficient photocatalysts and an increased understanding of the NO removal mechanism through photocatalytic technology.

Photocatalytic NO removal is an oxidation reaction where the NO2 or NO3− can be generated during the selective or non-selective NO removal process. For enhanced photocatalytic NO removal ability, photocatalysts were required stronger molecular oxygen activation activity for stronger oxidizability. Solid solution structure is confirmed as an efficient strategy to achieve induced molecular oxygen activation capacity. In this work, ultrathin structural BiOBr0.5I0.5 with oxygen vacancies (BiOBr0.5I0.5-U) was prepared and it showed obvious enhanced photocatalytic efficiency for NO removal than unmodified BiOBr0.5I0.5. The photocatalytic NO removal mechanism was confirmed through efficient methods. The enhanced generation ability for superoxide and singlet oxygen due to the ultrathin structure of BiOBr0.5I0.5-U was confirmed evidentially. The improved molecular oxygen activation activity supported the improved selective NO removal efficiency. This study could provide a new thought for the design of efficient bismuth oxyhalide photocatalysts for NO removal.

Carrier and exciton photocatalysis processes all occurred with bismuth oxyhalide photocatalysts according to previous researches, and the photocatalytic properties can be improved through optimizing any of these two processes. Herein, solid-heterostructural BiOBr0.5I0.5/Bi5O7Br0.5I0.5 with oxygen vacancies is synthesized and applied for environmental remediation, especially for some organic pollutants degradation. The improved photocatalytic organic pollutants degradation efficiency of BiOBr0.5I0.5/Bi5O7Br0.5I0.5 is due to the synergistic effect of both enhanced exciton and carrier photocatalysis due to the unique structure, which has been explored and explained by efficient characterizations. This work demonstrates a modified method for bismuth oxyhalide photocatalysts and provides a new thought for environmental remediation in a sustainable method.

Graphene (Gr), with robust barrier properties against corrosion ions, holds great potential application in waterborne epoxy coating for corrosion resistance, but hard to be realized for its intrinsic hydrophobicity. In comparison, graphene oxide (GO), with oxygen-containing functional groups on its surface, can be well dispersed in water but suffer the modest barrier properties for its defect can't effectively resist the permeability of corrosion ions. Herein, GO-Gr hybrids have been used in waterborne epoxy coating to overcome their shortcomings and enhance their advantages via the π-π interactions. The structure and morphology of the GO-Gr hybrids were characterized by Fourier transform infrared (FT-IR), X-ray diffraction (XRD), X-ray photoelectronic spectroscopy (XPS), Raman spectra, UV–vis absorption spectroscopy and transmission electron microscopy (TEM). Furthermore, the corrosion resistances of pure epoxy coating, GO/epoxy, and GO-Gr/epoxy were evaluated via electrochemical experiment and salt spray test. The results revealed that the GO-Gr/epoxy exhibited the highest corrosion resistance among these coatings owning to the synergistic effect of GO and Gr.

Improved photocatalytic NO removal of photocatalysts requires enhanced carrier photocatalysis for more reactive species generation. Ultrathin structural BiOBr/BiOI (BiOBr/BiOI-U) photocatalyst was in-situ prepared and it showed enhanced photocatalytic efficiency for NO removal. The underlying photocatalytic process is divided into two steps: in the first step, NO3– was produced in a nonselective oxidation process. The increased NO3– concentration induces NO3– adsorption on the surface oxygen vacancies of the photocatalyst in the second step, which changed the surface environment of the ultrathin BiOBr/BiOI photocatalyst. During this process, the nonselective oxidation process turned into a selective oxidation process with NO2 as the main product. In addition, the main photogenerated reactive oxygen species contributed to NO removal. Furthermore, the photocatalytic mechanism of BiOBr/BiOI-U was explored.

The BiOBrxI1−x/BiOBr heterojunction structural photocatalyst was constructed successfully in this work and it was formed by the BiOBrxI1−x solid solution coupling with the BiOBr monomer, which was determined by efficient characterizations. For the photocatalytic property, The BiOBrxI1−x/BiOBr could degrade some organic pollutants efficiently and the oilfield produced waste water treatment efficiency of it was ideal. The reason for its enhanced photocatalytic property was also explored. Through ESR tests, trapping experiments and other efficient methods, the enhanced molecular oxygen activation capacity of induced 1O2 and O2 − photogeneration by BiOBrxI1−x solid solution structure and heterostructure in one photocatalyst was confirmed, respectively. This work provided a new thought for enhanced molecular oxygen activation capacity of bismuth oxyhalide photocatalysts.

The emergence of the Internet has greatly promoted the progress of people’s production and lifestyle. With the rapid development of the network, the Internet is not only a communication technology, but also the largest information world in human history. This paper briefly introduces the Internet of Things and its architecture, and proposes a framework for Internet of Things service provision. However, on the premise of guaranteeing the real-time and reliability of resource providers’ own applications, the framework provides an infrastructure for customizable open and shared resources.

As an important part of the next generation of information technology, the Internet of Things has rapidly changed people’s lifestyles and promoted the development of productivity. In practical applications, the Internet of Things realizes user dynamic information processing through service combination to meet actual needs. Due to the particularity of Web services in service description objects, service resources and service environments in the IoT environment, existing Web service composition technologies It is difficult to apply directly to the Internet of Things. To this end, it is necessary to explore the service combination technology in the Internet of Things environment. This paper expounds the service architecture and related technologies of the service composition under the Internet of Things environment, and derives the content of the web service composition mechanism method. At the same time, the importance of QoS-based IoT service process is proposed.

Heavy metals in the water environment seriously threaten human health and the ecological environment. As an effective method for removing heavy metals in water, adsorption has attracted wide attention. Traditional LDHs materials are difficult to recover as adsorbents. This study provides a new type of adsorption material for Ni/Fe-LDH coated with sodium alginate(SA) synthesized by a simple hydrothermal method and treated with NaOH. Obtain the alkalized adsorption material alk-Ni/Fe-LDH-SA. It was characterized by SEM, XRD, FTIR, TGA and XPS, and its adsorption effect on Ni(II) and Cu(II) was studied. The experimental results show that the prepared Ni/Fe-LDH-SA adsorbent has an adsorption capacity of 182.8 mg/g for Ni2+ and 196.2 mg/g for Cu2+ at 25℃. It has good performance when pH ≥ 7, and after four cycles, the removal rate of the two ions remains above 80%. The analysis mechanism shows that the removal process is mainly through physical adsorption precipitation, electrostatic adsorption, ion exchange, and chelation. Compared with traditional adsorbents, the adsorbent prepared in this study is easy to be recycled and reused, and has potential application value to other heavy metal ions. It is a promising adsorbent material.

In this paper, we analyze the potential factors affecting the hydrogen sulfide type of stress corrosion cracking in C110 casing pipes. In order to further study these cracking factors, the methods of material property testing, scanning electron microscopy, XRD, TEM, and 3D ultra-depth-of-field were applied in the experiments. Besides that, an HTHP autoclave was independently designed by the laboratory to simulate the actual corrosion environment, and the potential factors affecting the stress corrosion cracking of C110 casing pipes were determined. The test results showed that the chemical composition, metallographic structure, hardness, and non-metallic inclusions of the two types of C110 casing pipes were all qualified. In fact, there remains a risk of stress corrosion cracking when the two kinds of C110 casing pipes serve under long-term field-working conditions. It is considered in this paper that the precipitates on the material surface, stress damage, and pitting corrosion are all critical factors affecting the stress corrosion cracking of casing pipes.

Bi5O7Br0.5I0.5 solid solution was firstly in-situ synthesized and the solid solution structure was determined by basic characterization. Here, Bi5O7Br0.5I0.5 showed enhanced photocatalytic ability for oilfield wastewater treatment than Bi5O7Br and Bi5O7I. Based on our study about photocatalytic mechanism, solid solution structure induced more singlet oxygen generation. It indicated that the origin of effective environmental photocatalytic activities should be enhanced exciton photocatalysis process of Bi5O7Br0.5I0.5 rather than the traditional carrier photocatalysis process. Due to the strong oxidizing property of singlet oxygen, the chemical oxygen demand (COD) value of oilfield wastewater reduced from 18,900 mg/L to 6800 mg/L after 5 h treatment. And the foul smell and black color of oilfield wastewater were disappeared. Except for oilfield wastewater, Bi5O7Br0.5I0.5 solid solution also displayed photocatalytic activity universality for dye and phenolic pollutants degradation. This work suggested that solid solution was an effective way to improve environmental photocatalytic activity via exciton photocatalytic process.

Previous reports have demonstrated that carrier and exciton photocatalysis processes all occur with BiOBr photocatalysts. The photocatalytic properties of BiOBr can be improved through optimizing a...

A new bismuth-rich Bi3O4ClxBr1−x solid solution photocatalyst was firstly synthesized through a solid phase conversion method. The X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), high-resolution transmission electron microscopy (HRTEM), UV–vis diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), and photoluminescence spectroscopy (PL) were used to characterize the physico-chemial properties of samples. Results demonstrated that Bi3O4Cl0.5Br0.5 had a higher activity than that of Bi3O4X (X = Cl, Br) for photocatalytic NO removal. The valence band XPS and photoelectrochemical analyses, theoretical calculation and scavenger trapping experiment indicated that Bi3O4Cl0.5Br0.5 had higher photocatalytic oxidation ability and effective prohibition the recombination of photo-induced charged carriers. This study suggested that solid solution should be effective approach to improve the photocatalytic activity of bismuth-rich photocatalysts for air purification.

Semimetal bismuth has attracted extensive interests, which were ascribed to the photo-thermal effect and co-catalyst properties. In this paper, Bi/Bi4O5I2 composites were synthesized through a molecular precursor hydrolytic process, and the sunlight induced semimetal Bi mediated photo-thermocatalysis of Bi4O5I2 for carbon dioxide to chemical energy was studied. When the optimal mole ratio of Bi: I was selected at 1.95:1, Bi/Bi4O5I2 displayed outstanding photo-thermocatalytic carbon dioxide to chemical energy (CO and CH4). Under simulate sunlight (UV–vis-IR) irradiation, the CO and CH4 generation over Bi/Bi4O5I2 enhanced to 40.02 μmol h−1 g−1, and 7.19 μmol h−1 g−1, respectively. The light to chemical energy (LTCE) conversion efficiency (80.2 × 10−6) was about 6.47 times than Bi4O5I2 (12.4 × 10−6), and 68.55 times than Bi4O5I2 without IR irradiation (1.17 × 10−6). The dramatically enhanced photo-thermocatalysis activity of Bi/Bi4O5I2 can be attributed to the co-catalyst and photo-thermal effect of Bi nanoparticles, which prohibiting the electron–hole recombination and accelerating light to thermal energy conversion, respectively. Furthermore, the enhanced photo-induced carrier separation rate and reaction system temperature of Bi/Bi4O5I2 was testified.

Simultaneous removal of petroleum and dye pollutants posed a huge challenge to the development of membranes. NH2-MIL-125 was widely used in separation membranes, but so far had not been used for oil/water separation. We successfully prepared NH2-MIL-125@polyacrylic acid (referred to as NH2-MIL-125@PAA) composite membrane on the PVDF by vacuum-assisted self-assembly technology. Due to the introduction of a large number of hydrophilic nanoparticles on the PVDF, the composite membrane exhibited excellent hydrophilicity and underwater oleophobic properties. At the same time, the membrane could efficiently separate oil/water emulsions and dyes. After 10 cycles, the separation rate of the oil/water emulsions and the dye was above 99%, and the flux was above 400 L / m 2 ∙ h . Moreover, due to the successful cross-linking of PAA and NH2-MIL-125, the membrane had good stability. Therefore, the composite membrane in this study provided an idea for the removal of multi-component pollutants.

Ti3C2 MXene contains suitable elements that are effective for photocatalysis, but it is usually not directly used for photocatalysis, which hinders its application in photocatalytic water treatment. In this work, we used the solvothermal method to grow MOF (Fe) in situ on Ti3C2 MXene to construct a composite schottky photocatalytic adsorbent. The morphology of the material is characterized by XRD, SEM, XPS, etc. The adsorption kinetic model and photocatalytic performance of the material were studied. The introduction of MXene avoids the agglomeration of MOF, increases the effective area of the composite material, and acts as a photo-generated electron trap in the photocatalytic process to enhance the charge separation efficiency of MOF. 10 mg composite material can remove more than 90% of MB (50 ppm) within 30 min, and remove 83.41% RhB (25 ppm) and 44.26% MO (20 ppm) within 120 min. In the case of a small amount of use, it shows good adsorption and photodegradation properties to a variety of dyes. Based on the experimental results, a dye removal mechanism based on adsorption performance and schottky knot synergistic Fenton effect is proposed. Its application can be used to eliminate and degrade pollutants in water.

Exciton and carrier photocatalytic processes have been proved in bismuth oxyhalogen photocatalysts. But, there are no reports about how to regulate the different mechanisms to improve photocatalytic activity for different reaction. Here, we found that the photocatalytic mechanisms could be regulated by changing the assembly method of bismuth, oxygen, and halogen atoms. Reactive oxygen species (ROS) experimentals results concluded that solid solution BiOBr0.5I0.5 showed enhanced exciton photocatalytic process, and coupling 0.5BiOBr/0.5BiOI displayed improved carrier photocatalytic proces. This work promoted the understanding about solid solution and coupling for bismuth oxyhalogen.

Bismuth oxyhalides (BiOX, X = Br, I) photocatalysts are rarely applied for photocatalytic reduction reaction withthe photo-induced electron, as this is impeded by their low conduction band. As a widely used approach for enhancing the photocatalytic reduction activity, bismuth-rich strategy results the bismuth content of BiOX photocatalysts increasing. In this paper, a solid solutions of bismuth-rich Bi4O5BrxI2-x were prepared applying the molecular precursor method. Bi4O5BrxI2-x were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), element mapping, Brunauer–Emmett–Teller surface analysis (BET), UV–vis diffuse reflectance spectroscopy (DRS), and X-ray photoelectron spectroscopy (XPS). The obtained photocatalytic data showed that Bi4O5BrxI2-x solid solutions had higher photocatalytic activities than Bi4O5Br2 and Bi4O5I2. At an optimal ratio of x = 1, the Bi4O5BrI photocatalyst showed the highest photocatalytic reduction activity for CO2 conversion (22.85 μmol h−1 g−1 CO generation, AQE was 0.372 at 400 nm) and Cr(VI) removal (88%). CO2 adsorption data and CO2 temperature programmed desorption (CO2-TPD) revealed that Bi4O5BrI exhibited the highest chemical adsorption ability of CO2 molecules Photocurrent and electrochemical impedance (EIS) spectroscopy demonstrated the enhanced photo-induced carrier separation efficiency of Bi4O5BrI. These mechanistic studies suggest that Bi4O5BrxI2-x solid solutions are excellent photocatalysts for solar fuel generation and environmental remediation.

We report the fabrication of poly(2-acrylamide-2-methylpropanesulfonic acid) modified SiO2 (SiO2/PAMPS) nanoparticles as plugging agents in water-based muds (WBMs). SiO2/PAMPS nanoparticles were prepared by the copolymerization of 3-methacryloxypropyltrimethoxysilane-functionalized SiO2 nanoparticles and 2-acrylamide-2-methylpropanesulfonic acid. These SiO2/PAMPS nanoparticles were found to exhibit excellent salt tolerance, thermal stability, and good compatibilities with polymeric additives commonly used in WBMs. The plugging capabilities of the nanoparticles were tested with filter cakes on a high-temperature, high-pressure filtration press. The results indicated that SiO2/PAMPS nanoparticles can effectively block the nanopores in filter cake. In addition, WBMs containing SiO2/PAMPS nanoparticles were found to exhibit excellent plugging properties both at ambient temperature and at 80 °C, demonstrating that these nanoparticles are promising plugging agents in WBMs for drilling in shale formations.

Surface plasmon resonance (SPR) and Z-scheme bridge are the most important roles of noble metal nanoparticles for photocatalysis. In this study, the size-dependent role of gold (Au) in Au/g-C3N4/BiOBr system was studied for photocatalytic CO2 reduction and dye degradation. The results revealed that big Au nanoparticles mainly displayed Z-scheme bridge role, and g-C3N4/BiOBr/Au-B showed higher photocatalytic activity than g-C3N4/BiOBr under 380 nm monochromatic light irradiation. Small Au nanoparticles mainly displayed SPR role, and g-C3N4/BiOBr/Au-S showed higher photocatalytic activity than g-C3N4/BiOBr under 550 nm monochromatic light irradiation. The size-dependent role of Au nanoparticles for photocatalytic system should be due to the SPR effect of small Au nanoparticles and electron transfer center of big Au nanoparticles. This finding can guide us to prepare high photocatalytic activity noble metal loaded photocatalysts.

The acceleration of urbanization leads to higher standards and requirements for Internet of Things matching technology. Based on this, the matching technology of Internet of things based on multiple linear regression model in urban management is put forward. Data in the Internet of Things are processed accurately. Wireless sensors with optimal functions are selected, and mathematical models are established and solved. Through experimental demonstration, it is concluded that the Internet of Things matching technology based on multiple linear regression model greatly reduces the cost of urban management.

Understanding the appearance and maintenance of cooperation behavior is one of the most interesting challenges in natural and social sciences. Evolutionary game is a useful tool to study this issue. Here, we consider a basic strategy updating rule: the probability of a player updating its strategy is affected by the learning ability, which is determined by payoffs and an aspiration parameter [Formula: see text]. For positive [Formula: see text], learning ability is directly proportional to player’s own payoff. When [Formula: see text] equals 0, it returns to traditional situation. It is found that increasing the value of [Formula: see text] can promote the cooperation. With the increase of [Formula: see text], the player’s learning ability is continuously enhanced, and the probability of changing strategies is also increased. This paper verifies the influence of the introduced selection parameter [Formula: see text] on the cooperation rate from different aspects. We tested this hypothesis through the Monte Carlo simulation, and demonstrated that introducing [Formula: see text] changed the network of interaction effectively, therefore changing the effect of the adoption of the strategy on the uncertainty of cooperation evolution. This paper analyzed the results of the payoff-dependence learning ability of different players when they imitate the strategies of their opponents, which can effectively promote the evolution of cooperation.

In this research, the main aim is to take the advantages of both graphene (Gr) and polyaniline (PA) in enhancing the barrier property and self-healing performance of composite coating. Herein, hollow polyaniline (HOPA) was prepared by sacrificing template method, which not only acted as a dispersant to enhance the dispersion of Gr nanosheets via the π-π interactions, but also was used as a nano container for storing benzotriazole (BTA) corrosion inhibitor. In addition, insoluble Cu-BTA complex stoppers possessed H+ ion-responsive inhibitor release property. The final release concentration of BTA in Gr/HOPA carrier was as high as 274.55 ppm, which was about 2.3 times than that of PA (120.42 ppm) due to the formation of cavity structure. From the EIS results of intact coatings, the 0.7 % of Gr/HOPA/BTA@Cu loaded composite coating exhibited a remarkable corrosion protection capability after 130 days of immersion. And the scratch test indicates that the Gr/HOPA/BTA@Cu based composite coating showed more long-term self-healing effect than that of Gr/PA/BTA@Cu/epoxy sample, which was related to the high BTA loading rate in HOPA.

Faced with severe corrosion of casing in oil wells, the epoxy coating was applied to prevent corrosion. Based on the mechanism that the filler eliminated the internal stress during the curing process of the coating and prevented the penetration of corrosive medium into the coating, a new filler was successfully prepared by the hydrothermal method. When the molar ratio of the precursor of ZrO2 to MoS2 was 1.2:1, MoS2 was uniformly modified with ZrO2 through mussel inspired chemistry of dopamine. Introducing fillers into epoxy coatings, specifically, a proper content of 0.8 wt.% filler can greatly improve the mechanical properties and corrosion resistance of the coatings. The coating maintained the excellent corrosion resistance for 16 h under high temperature (108 °C) and high pressure (pressurized with CO2 gas of 35 MPa), which would provide us a reliable anticorrosive coating for oil wells metal casing.

Shale hydration is the main cause of wellbore instability during drilling using water-based drilling fluids (WBD). In this work, NH2- and HO-functionalized ionic liquids (ILs) were investigated for their performances on inhibiting the shale hydration, as well as their influences on the properties of WBD, using immersion and sedimentation tests, linear swelling test, hot-rolling dispersion test, rheological and filtration experiments. The mechanisms were identified by X-ray diffraction (XRD), zeta-potential and particle size distribution analyses, scanning electron microscopy (SEM) and related theoretical analysis. Evaluation experiment results showed that the NH2-functionalized IL had the best inhibition performance, followed by poly(propylene glycol)bis(2-aminopropyl ether), HO-functionalized IL and KCl. NH2-functionality was more favorable to shale inhibition than HO-functionality. When used in WBD, ILs could prevent viscosity building-up at high temperature, but cause filtration and inhibition failure, which could be mitigated when polyanionic cellulose (PAC) was added in WBD prior to inhibitors. Three critical observations helped elucidate the inhibitive mechanisms: the intercalation of cationic groups of ILs into the clay interlayers, the decrease of both interlayer spacing and double layer thickness. The NH2-functionalized IL allowed the smallest interlayer spacing and double layer thickness and therefore performed best in inhibition. The inhibition failure in WBD with ILs depended on two aspects: the consumption of ILs untimely and the filtration failure of WBD. PAC could decrease both of ILs’ loss within WBD and water loss toward shale, mitigating the WBD’s inhibition failure. Our work will facilitate the rational design of efficient and environmentally acceptable inhibitors and their rational applications in WBD for drilling shale formation.

In this work, 3D BiOBr microspheres were successfully synthesized via a solvothermal method with different bromine source. The as-fabricated samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), UV–vis diffuse reflectance spectroscopy (DRS), and X-ray photoelectron spectroscopy (XPS). Compared their photocatalytic performance for CO 2 reduction, BiOBr-IL showed the highest activity and selectivity. It suggested that the [Bmim]Br ionic liquids assisted synthesis method was an successful way to improve the photocatalytic performance for CO 2 reduction of BiOBr.

Until now, BiOBr and BiOI are not used for photocatalytic H2 evolution due to the positive CB position. In this work, bismuth-rich strategy is used to promote the CB position. Bi4O5X2 (X = Br, I) nanosheets with dominant {1 0 1} facets exposure are synthesized by molecular precursors hydrolysis route. Bi4O5Br2 and Bi4O5I2 samples were characterized by X-ray diffraction patterns (XRD), transmission electron microscopy (TEM), UV–vis diffuse reflectance spectra (DRS), X-ray photoelectron spectroscopy (XPS) and photoelectrochemical measurements. Bi4O5Br2 displays higher photocatalytic activity than Bi4O5I2 for H2 production. And the H2 evolution rate of Bi4O5Br2 reach 6.81 μmol h−1 with the apparent quantum efficiency of 0.93% at 420 nm. It is the first work to report photocatalytic H2 production using Bi4O5X2 photocatalysts.

Heterojunction is an effectively construction to improve the photocatalytic activity due to the excellent photo-induced carrier separation efficiency. In this paper, g-C 3 N 4 /Bi 4 O 5 I 2 heterojunction was prepared and characterized by X-ray diffraction patterns (XRD), field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM), UV–vis diffuse reflectance spectra (DRS) and X-ray photoelectron spectroscopy (XPS). The photocatalytic data showed that g-C 3 N 4 /Bi 4 O 5 I 2 heterojunction had higher activity than pure g-C 3 N 4 and Bi 4 O 5 I 2 . At an optimal ratio of 1.0 mol% (11.4 wt% of Bi 4 O 5 I 2 ), g-C 3 N 4 /Bi 4 O 5 I 2 photocatalyst showed the highest photocatalytic reduction activity for CO 2 conversion with 45.6 μmol h −1 g −1 CO generation. Photocurrent and electrochemical impedance (EIS) spectroscopy revealed that higher photo-induced carrier separation efficiency of g-C 3 N 4 /Bi 4 O 5 I 2 . Z-scheme charge transfer mode was proved by I 3 − /I − redox mediator existence and superoxide radical (O 2 − ) and hydroxyl radical ( OH) quantification experiments.

Photocatalysis is a green and economical method to convert greenhouse gases such as carbon dioxide (CO2) for environmental remediation and solar fuel generation. In a semiconductor photocatalyst system, cocatalysts play a very important role. They are not only redox-active sites but also can be used to improve the separation efficiency of photo-induced carriers. In this work, a dual-cocatalyst-loaded Au/BiOI/MnOx photocatalyst was prepared to enhance the photocatalytic reduction activity for the conversion of greenhouse gases (CO2) into solar fuels. The as-prepared BiOI, Au/BiOI, MnOx/BiOI and Au/BiOI/MnOx were characterized by using X-ray diffraction patterns (XRD), the Brunauer–Emmett–Teller (BET) method, transmission electron microscopy (TEM), UV-vis diffuse reflectance spectra (DRS) and X-ray photoelectron spectroscopy (XPS). The photocatalytic reduction results showed that Au/BiOI/MnOx had higher activity than pure BiOI, MnOx–BiOI, Au–BiOI and other BiOI-based photocatalysts for solar fuel generation. Photocurrent and electrochemical impedance (EIS) spectroscopy revealed that the efficient photo-induced carrier separation efficiency of Au/BiOI/MnOx induced the high photocatalytic activity.

Tannic acid (TA), as a biodegradable corrosion inhibitor, was used to modify the graphene (Gr) for improving the water-dispersibility of Gr. Further, the polyaniline (PANI) was enwrapped on the vanadium pentoxide (V2O5) surface to increase its conductivity, thus promoting rapid formation of passivation film. Besides, the PANI enwrapped vanadium pentoxide (PV) was self-assembled with the Gr-TA through π-π interaction. Then, the waterborne epoxy coating (WEC) filled with the Gr-TA@PV hybrids were prepared, and the corrosion protection performance of the nanocomposites WEC were investigated through electrochemical and salt spray tests. The results confirmed that the outstanding corrosion protection performance of Gr-TA@PV/WEC derived from the superior barrier property of Gr nanosheets for corrosion agents and its self-healing effect. The self-healing process includes the formation of TA-Fe-TA complex and a passive Fe2O3/ Fe3O4 layer at the interface of coating/substrate.

Epoxy coatings play an important role in preventing the corrosive medium penetrating into the base metal, but improving its durability in harsh environments is still a challenge. Nanomaterial introduced in epoxy coatings is an effective improvement measure, especially, the use of two-dimensional nanomaterial can effectively block the corrosion medium. In this paper, we use two-dimensional molybdenum disulfide (MoS2) hybrid materials as nanofiller to improve the corrosion resistance of epoxy coatings. MoS2 hybrid materials were obtained by an effective method based on self-oxidation of dopamine and functionalized silane (KH560) grafting. The poly(dopamine) and epoxy groups on the surface of MoS2 enhanced the interaction with EP matrix. The anticorrosive performance of composite epoxy coating with the different content of MoS2 hybrid materials was investigated in detail. An appropriate content (0.8 wt%) in the epoxy coating was obvious to improve its anti-corrosion performance.

Self-healing coatings, possessing an “active healing” ability to repair physical damage and to prolong the life of coating without external intervention, are of current interest. Herein, a novel self-healing coating, by using aspartic acid intercalated layered double hydroxide (AA-LDH) @ reduced graphene oxide (RGO) as filler within epoxy has been demonstrated. The corrosion protection performance and self-healing ability of composites coatings have been investigated via electrochemical impedance spectroscopy (EIS) and salt spray test. The AA-LDH@RGO/epoxy exhibits excellent corrosion resistance owing to the high barrier properties of RGO for corrosive ions. Moreover, the epoxy loaded with AA-LDH@RGO shows outstanding self-healing performance, attributing to the release of AA from LDH on the basis of the ion exchange performance, thus leading to formation of AA-Fe-AA compounds at the coating/steel interface. The results clarified that the addition of AA-LDH@RGO increases the impedance of the epoxy resin from 6.437 × 106 to 2.112 × 109 Ω cm2, and effectively extends the epoxy coating failure time to 40 days.

With the increasing presence and adoption of the smart device in the Internet of Things (IoT), the service recommendation is becoming more and more important. In this paper, we proposed a service recommendation scheme based on the mass diffusion dynamic tag tripartite graph. We extracted the users' habit features of using the IoT device service as the dynamic tag and then built the tripartite graph. Through the positive and backward mass diffusion on the tripartite graph, we got the resource value of the service. We finally obtained the recommendation list through the comprehensive calculation of the energy state, the user similarity, the bearing capacity, and the service resource value of the mass diffusion results. The experiments showed that the recommendation precision of the service recommendation scheme we proposed was at least 12% higher than the other algorithms.

In this article, we research on the service recommendation strategy in the IoT. The user attribute similarity and the attribute correlation of user and device service are computed, and the recommendation system is recommended based on the calculation results. In order to solve the cold start problem, we propose the tensor linear regression model. The experiment results show the recommendation strategy was effective.

A series of biodegradable polymers was prepared by solution co-precipitation of poly(para-dioxanone) (PPDO) and poly(lactic-co-glycolic acid) (PLGA) in various blend ratios. Samples were compression-molded into bars using a platen vulcanizing press. The miscibility, thermal and mechanical properties of the materials were investigated using differential scanning calorimetry (DSC), polarized optical microscopy, and scanning electron microscopy (SEM). Dynamic contact angle was used to characterize the water wettability of PLGA/PPDO blends. The mechanical properties of blends and pure polymers were measured by tensile tests. The position of the glass transition temperatures (T g ) was dependent upon composition. When 10 % PLGA was added into PPDO, the DSC curve revealed only one T g (−7.35 °C) which was located between the T g values of PPDO and PLGA. When 20 % PLGA was added into the blend, two independent T g values for PPDO/PLGA blends were observed, and such characteristics improved further upon addition of 30 % PLGA. SEM images of fractured surfaces displayed evidence of the morphology of PPDO/PLGA blends that were consistent with the DSC results. Hence, a relationship was found between homogeneity and the contents of PLGA in the blend. The compatibility of the blends increased with addition of small amounts of PLGA, followed by a leveling-off at higher content.

Molybdenum disulfide (MoS2) with the defect-rich sites was prepared, and further functionalized by epoxy groups, obtaining the hybrid materials (KH560-MoS2). The microstructure and composition of KH560-MoS2 were characterized by SEM, TEM, XRD, Raman, and XPS, which those results demenstrated that KH560-MoS2 was successfully modified by gamma-(2, 3-epoxypropoxy) propyl-trimethoxy silane (KH560) on the defect-rich MoS2 nnaosheets. In addition, KH560-MoS2 nanosheets were introduced into epoxy coating. Moreover, the influence of the amount (0 wt%, 0.2 wt%, 0.5 wt%, 0.8 wt%, 1.0 wt%, 1.5 wt%) of KH560-MoS2 on corrosion resistance of epoxy coating was studied by electrochemical impedance spectroscopy (EIS) and salt spray test, which showed that epoxy coating with the 0.8 wt% KH560-MoS2 exhibited the remarkable superiority in enhancing the anticorrosion performance.

Graphene oxide (GO), BiOBr and graphene–BiOBr nanosheets composites (BiOBr–RG) were synthesized and characterized. It can be found that except for BiOBr nanosheets with pure tetragonal phase were grown uniformly on the graphene surface, little graphene layer also can load on the surface of BiOBr evenly. And we found that the graphene can change the conduction band (CB) and valence band (VB) of BiOBr toward enhanced photocatalytic activity for reactive oxygen species (ROS) generation than that of BiOBr under visible-light irradiation.

Graphene oxide (GO), tungsten trioxide (WO3) and graphene–WO3 nanobelt composites (GW) were synthesized and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), UV–vis diffuse reflection spectra (DRS) and X-ray photoelectron spectroscopy (XPS) valence band spectra. We demonstrated that the graphene can elevate the conduction band of WO3 toward photocatalytic reduction of CO2 into hydrocarbon fuels under visible-light irradiation. And the photocatalytic activity of GW is higher than that of GO, WO3 and P25 TiO2.

Uniform anatase TiO 2 microspheres with a high percentage of exposed {001} facets have been successfully synthesized by a one-step hydrothermal strategy in the presence of H 2 O 2 and (NH 4 ) 2 CO 3 solution. The as-synthesized anatase TiO 2 microspheres with exposed {001} facets exhibited higher photocatalytic selectivity for degradation of methylene blue and methylene orange mixed solution under UV light irradiation at room temperature than anatase TiO 2 microspheres without {001} facets exposing and P25 TiO 2 .